The Viking practice of filing their teeth has only been recently uncovered. A study from 2005 discovered 22 males from Viking Age Sweden who had filed teeth. Archaeologist Caroline Arcini wrote that “the marks are skilfully made, and it is most likely that the individuals did not make the marks themselves, but that someone else must have ﬁled them.”Via Medievalists.net, citing Caroline Arcini’s article ‘The Vikings bare their filed teeth’ in the American Journal of Physical Anthropology, Volume 128, Issue 4 (2005)
Most Vikings did not have such dental work done, which is perhaps not unsurprising considering that the filing of teeth would have been an extremely painful procedure. The filings were done on the top set of the teeth in the front, and in her study Arcini notes that they were generally similar in design. She adds that to show off the teeth the Viking male would have had to smile broadly. Furthermore she speculates that they may have even coloured their teeth as well, explaining “Maybe they mixed some color with fat or wax before putting it on the teeth, e.g., fat and charcoal to get a black line."